Valve and heat exchanger assembly



K. O. PARKER ETAL VALVE AND HEAT EXCHANGER ASSEMBLY Filed June 2, 1958 ik N fllllllll 'e/ United States Patent O 3,145,768 VALVE AND HEAT EXCHANGER ASSEMBLY Kenneth i). Parker and Robert L. Campbell, Dayton,

Ohio, assignors to United Aircraft Products, Inc., Daytion, Ohio, a corporation of Ohio Filed .lune 2, 1958, Ser. No. '739,224 2 Claims. (Cl. 16S- 39) This invention relates to Valve and heat exchanger assemblies, and although not so limited has special application or reference to small and light weight integrated devices of the kind described for use in aerial craft.

An object of the invention is to adapt assemblies as described to the use of high pressure, high temperature compressor bleed air is a source of heat to warm fuel and like purposes.

Another object of the invention is to construct a modulating type valve for an accurate control over a tlowing high pressure, high temperature iluid such as compressor bleed air through thermally responsive or like means while substantially obviating the eifects of iluid pressure upon the valve.

A further object of the invention is to adapt a heat exchanger in an assembly as described for yielding under applied temperature differentials whereby to avoid such inadvertent dislocation of parts as would permit an exchange of iluid between separated fluid systems.

' Still another object of the invention is to present a generally new light weight valve and heat exchanger assembly in which the foregoing objectives are achieved in a simple and reliable manner and result in a compact, relatively inexpensive and reliable article of manufacture.

Other objects and structural details of the invention will appear from the following description when read in connection with the accompanying drawing, which is a View in longitudinal section of a light weight valve and heat exchanger assembly in accordance with the illustrated em-v bodirnent of the invention.

Referring to the drawing,in accordance with such illustrated embodiment, a valve and heat exchanger assembly comprises a cylindrical open ended heat exchanger casing or shell 1.0 and a similar valve casing il. The casings and 11 are in parallel adjacent relation to one another and physically interconnected through external pads l2 and 13 thereon. These latter devices are secured to respective casings and have their exposed surfaces in contacting relation to one another, as indicated, to position the valve and heat exchanger casings substantially as illustrated. The pads 12 and 13 are suitably secured to one another to provide a substantially integral valve and heat exchanger assembly. The pads l2 and 13 have through openings therein which cooperate with corresponding openings in one another to provide longitudinally spaced apart through passes 14 and i5. At its upper end the pass 14 is aligned with a radial opening 16 in heat exchanger casing lll. At its lower end pass 14 is aligned with radial opening 17 in the valve casing 11. Similarly, lateral pass is aligned with a radial opening 13 in the casing 1li at its upper end and with a radial opening 19 in the casing 11 at its lower end. The lateral passes 14 and 15 accordingly intercommunicate the interiors of the casings 10 and l1.

At its upper end, the lateral pass 14 communicates with a chamber 21 in the casing 10 defined by an end insert 22 and a perforated tube sheet or header 23 installed in the casing lll between the lateral passes 14 and 15. The header 23 mounts the one ends of heat exchange tubes 24 which open into the chamber 21. The opposite ends of the tubes 24 are similarlyinstalled in a like tube sheet or header 25. Such opposite tube ends extend through the tube sheet 25 to communicate with a chamber 2d on the opposite side thereof defined by tube sheet 25, end

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insert 27 and a cylindrical sleeve 28 which surrounds tube sheet 25 and end insert Z7 and is received in an expanded end of the casing 10.

Intermediate the header plates or tube sheets 23 and 25 the casing 10 is formed with a further lateral opening 2.9. A lltting 31 is mounted on the exterior of casing 1i! in registering relation to opening 29 to conduct lluid out of the heat exchanger casing as will hereinafter more clearly appear. Within the casing l0 is a series of baffles 32 providing support for intermediate portions of the tubes 24. Approximately centered in the casing is a further, vertically disposed, baflle 33 tending to enforce a cross-how movement within the casing over the tubes 24, in two passes from the lateral pass 1S to the outlet opening 29. Lateral pass 15 and outlet 29 are in common communication with the interior of casing lil, between the tube sheets 23 and 25 and on opposite sides of vertical baille S3.

The end insert 27 has an opening 34 therein to admit to the chamber 26 another iluid to pass through the tubes 24. This iluid collects in the chamber 2o and then flows through the tubes 24 to the chamber 21 and collecting in this chamber then is permitted to ilow by way of lateral pass lll from the heat exchanger casing into the valve casing. More particularly, the iuid enters a chamer 53 in valve casing 1l as defined by an end closure 36 and an intermediate partition Si. A lateral opening 38 over which is mounted a fitting 39 provides a fluid outlet from the chamber 35.

The lateral pass l5 communicates at its upper end, as noted with the interior of heat exchanger casing itl between the tube sheets 23 and 25. The lower end of lateral pass 15 communicates with a chamber il in the valve casing il as defined by the intermediate partition 37 and an end insert comprising a bushing 42 and an installed fitting 43. The fitting 43 has a continuously open passage 44ttherein terminating in an opening 45 communicating with casing 41 and aligned with the longitudinal axis of casing il. Denning the opening 45 is a cylindrical portion d6 of the iitting 43 which provides a valve seat engageable by the conical nose o7 of a valve assembly 4d. From the center of the nose portion 47 of the valve assembly itl a shaft 49 extends inwardly of the valve casing 11 and has a bearing in an extension 51 of the partition 37 projecting into the valve casing chamber 3S. The extension 51 is formed With a bore 52 and a counter-bore S3. The latter receives the shaft i9 while a reduced diameter portion 54 of the shaft 49 projects into and through the bore S2, having a sliding tit therein. Beyond the extension Si, the reduced diameter portion 54 of the shaft i9 is coupled by means including a transverse pin 55 to a plunger 56 extending from a thermostatic device 57 having a mounting in and in effect forming a part of the closure 36 at the one end of the valve casing. ln accordance with the known construction and mode of operation of the device 57, a thermally responsive material therein expands under the influence or" rising temperature and projects the plunger 56 outwardly or to the right as viewed in the drawing. Under a lowering temperature, the thermally sensitive material is permitted to be recompressed, as by suitable spring means, with the result that the plunger 56 is retracted or withdrawn leitwardly as viewed in the drawing. The thermostatic device 57 is stationed in a central position in the chamber 35 to be washed by fluid ilowing from the lateral pass 14 through the chamber' 35 to outlet 3%. It is, accordingly, aftected by and responds to changing temperature of the iluid which enters the assembly by way of opening 34, passes through the tubes 2d, and is conducted by lateral pass 14 to the valve casing and out of the assembly by way of outlet 38. Extending and retracting movements of the plunger 56, it will be understood, effect or result in corresponding axial movements 3 of the valve assembly 4S toward and away from the seat 46. A greater or lesser restriction to flow through the opening 45 thereby is exerted, with a modulating effect upon the flow rate of the fluid from fitting passage 44 to chamber 41 in the valve casing.

The conical valve portion 47 merges with a cylindrical portion 58 extending in surrounding relation to the shaft 49 into a sleeve 59 integral with the partition 37 and projecting into the chamber 41. A flange 6l on the cylindrical portion 58 has a sliding bearing in the sleeve 59. An interior chamber 62 thereby is defined continuously supplied with pressure fluid from the inlet opening d by small diameter openings 63 in the nose portion 47 of the valve, the opening 63 being positioned to be constantly communicating with the opening 45 irrespective of the position of the valve. Filter means, including a cylindrical filter 64 and a lock ring 65 may be stationed in the chamber 62 in surrounding relation to the shaft i9 to cleanse iiuid which may flow to the bearing surface provided by sleeve 59 from foreign particles which may interfere with the free sliding movement of the valve.

Segregation of the fluids on opposite sides of the partition 37 is enforced by a sealing assembly recessed in the shaft 49 and comprising a deformable rubber composition O-ring 65 anked by back-up rings 67 made of a synthetic material, for example Teflon. Beyond the described sealing assembly the bottom of the counter-bore 53 is vented by an opening 68 communicating with a chamber 69 connected to a place of low or ambient pressure. Within bore 53 is a further sealing means 71 on the reduced diameter shaft portion 54.

The mode of operation of the valve unit will largely be self-evident from the foregoing description, taken in connection with the drawing. Briefly, however, the thermostatic device 57 senses the temperature of the outgoing fluid in chamber 35 and makes a compensating adjustment of the valve 48 toward or from the seat 45 as may be indicated by the departure of the fluid temperature in chamber 35 from a pre-determined value. According to a feature of the invention, the fluid supplied to the assembly by way of fitting 43 is high temperature, high prescompressor bleed air. In an open position of the valve 48 this air ows around the outside of nose portion 47, through the opening 45 and around cylindrical portion 58 of the valve to lateral pass 15. By Way of this pass, the heated air enters the heat exchanger casing and flows over and around the tubes 24 and leaves the heat exchanger by Way of opening 29 and outlet fitting 31. Longitudinal adjustment of the valve 4S relatively to seat 46 enables greater and lesser amounts of the heated air to reach the heat exchanger casing with the result that greater and lesser amounts of heat are available for absorption into the fluid flowing through the tubes 24, it being understood in this connection that the fluid flowing through the tubes 24 is supplied to chamber 26 under pressure and passes continuously through the assembly. In the illustrative embodiment of the invention the end purpose of the assembly is to warm liquid fuel flowing to an engine in order that freezing at the engine jets may be obviated. For a more sensitive response to the thermostatic device 57, and thereby to changing temperature in the chamber 5S, the valve 43 is balanced or substantially balanced against the effects of the high pressure incoming air at opening 45. This is accomplished by admitting air at the inlet to the interior of the valve by way of openings 63 where it is applied to all exposed surfaces in opposition to the pressure at the outside of the valve bearing on the nose thereof. The arrangement is one relieving the thermostatic device 57 largely of the necessity for overcoming opposing pressures at the inlet 45 whereby the positioning of the valve becomes more nearly a true function of temperature in the chamber 35.

The Teflon back-up rings 67 are resistant to high ternperatures and will serve to limit air leakage in the event of failure of the rubber composition O-ring 66. Also, since the Teflon is a highly lubricating material it tends to fill surface irregularities and reduce wear of the O-ring.

The floating arrangement of the tube sheet 25, insert 27 and inlet chamber 26 allows the shell l0 and tubes 2d to change length in different amounts due to different temperatures. Shell lll is in contact only with the heated fluid and may take on a very high temperature as on the order of 700 F. The tubes 24, however, are in contact with both the relatively cool fuel and the heated uid and assume a resultant temperature which may be several hundred degrees lower than the shell temperature. In the absence of permitted relative motion, which tends to be produced by this temperature differential, stresses and failure may result were both tube sheets 23 and 25 rigidly connected to the casing 10. The instant iioating construction permits the heat exchanger casing or shell to extend and contract relatively to the core of the heat exchanger as represented by the tubes and tube sheets.

The assembly is adapted for fabrication by brazing techniques, all or most of which can be carried out in a single operation. The header or tube sheet 25, insert 27 and sleeve 28 constitute an integrally brazed assembly. The tubes 24 are brazed into the tube sheets 23 and 25 and tube sheet 23 and insert 22 are brazed into the casing 10. Similarly, the partition 37, bushing 42 and a like bushing 72 receiving the closure 36 are in a like manner united with the valve casing lll. As indicated by the arrows 73 fluid winch escapes from chamber 52 by flowing around flange 61 enters chamber 4l and so is conducted to pass 15.

What is claimed is:

1. A fuel heater or like device to be interposed in lines flowing high temperature air under pressure and relatively cool fuel under pressure, including a heat exchanger casing, a valve casing in parallel adjacent relation to said heat exchanger casing, said casings being joined together in a unitary assembly, a pair of spaced apart lateral passes intercommunicating the interiors of said casings, tube sheets installed in said heat exchanger casing on opposite sides of one of said passes, one of said tube sheets being made fast relatively to the heat exchanger casing and the other being slidable therein, the other one of said passes being located between one of said tube sheets and corresponding ends of said casings, said ends being closed, tubes having their opposite ends installed in and secured to respective tube sheets, means to introduce the relatively cool fuel between the other one of said tube sheets and the opposite end of said heat exchanger casing, said fuel flowing through said tubes to the said other one of said passes and being communicated thereby to the interior of Said valve casing, an outlet from said valve casing for said fuel, a partition in said valve casing between the said other one of said passes and the opposite end of said casing, said one pass communicating with the interior of said valve casing between the said opposite end thereof and said partition, means to introduce the high temperature air into said valve casing at said opposite end thereof, including a passage in said valve casing through which said air flows, a Valve controlling the rate of flow through said passage, thermally sensitive means in said valve casing responding to a changing temperature of said fuel therein, a connection between said thermally sensitive means and said valve through said partition to adjust said valve under control of said thermally sensitive means relatively to said passage, an outlet for said air from the interior of said heat exchanger casing between said tube sheets, said outlet for air being located adjacent to the said other one of said tube sheets while said one pass admitting air to said heat exchanger casing is located adjacent to said one tube sheet, said outlet for air and said one pass being on the same side of said heat exchanger casing, and a baille in said heat exchanger casing projecting from said same side thereof intermediate said outlet for air and said one pass in transverse relation to said tubes, the movement of air in said heat exchanger casing being counter to the direction of flow of the fuel and around said baille in generally cross-How relation to said tubes.

2. A fuel heater or like device according to claim 1, wherein said valve is arranged to close in a direction opposed to the direction of ow of said air, characterized by means substantially to balance said valve against the effects of such air ow thereon.

Kibby Feb. 27, 1912 Hayes Nov. 9, 1926 6 Snader July 26, 1927 McNeal Mar. 19, 1935 Shaw July 6, 1948 Currie Nov. 22, 1949 Lucke .Tune 27, 1950 Clark Apr. 28, 1953 Carroll et a1 Oct. 15, 1957 Andersen Oct. 29, 1957 Booth et al Dec. 16, 1958 FOREIGN PATENTS Great Britain Mar. 25, 1899 

1. A FUEL HEATER OR LIKE DEVICE TO BE INTERPOSED IN LINES FLOWING HIGH TEMPERATURE AIR UNDER PRESSURE AND RELATIVELY COOL FUEL UNDER PRESSURE, INCLUDING A HEAT EXCHANGER CASING, A VALVE CASING IN PARALLEL ADJACENT RELATION TO SAID HEAT EXCHANGER CASING, SAID CASINGS BEING JOINED TOGETHER IN A UNITARY ASSEMBLY, A PAIR OF SPACED APART LATERAL PASSES INTERCOMMUNICATING THE INTERIORS OF SAID CASINGS, TUBE SHEETS INSTALLED IN SAID HEAT EXCHANGER CASING ON OPPOSITE SIDES OF ONE OF SAID PASSES, ONE OF SAID TUBE SHEETS BEING MADE FAST RELATIVELY TO THE HEAT EXCHANGER CASING AND THE OTHER BEING SLIDABLE THEREIN, THE OTHER ONE OF SAID PASSES BEING LOCATED BETWEEN ONE OF SAID TUBE SHEETS AND CORRESPONDING ENDS OF SAID CASINGS, SAID ENDS BEING CLOSED, TUBES HAVING THEIR OPPOSITE ENDS INSTALLED IN AND SECURED TO RESPECTIVE TUBE SHEETS, MEANS TO INTRODUCE THE RELATIVELY COOL FUEL BETWEEN THE OTHER ONE OF SAID TUBE SHEETS AND THE OPPOSITE END OF SAID HEAT EXCHANGER CASING, SAID FUEL FLOWING THROUGH SAID TUBES TO THE SAID OTHER ONE OF SAID PASSES AND BEING COMMUNICATED THEREBY TO THE INTERIOR OF SAID VALVE CASING, AN OUTLET FROM SAID VALVE CASING FOR SAID FUEL, A PARTITION IN SAID VALVE CASING BETWEEN THE SAID OTHER ONE OF SAID PASSES AND THE OPPOSITE END OF SAID CASING, SAID ONE PASS COMMUNICATING WITH THE INTERIOR OF SAID VALVE CASING BETWEEN THE SAID OPPOSITE END THEREOF AND SAID PARTITION, MEANS TO INTRODUCE THE HIGH TEMPERATURE AIR INTO SAID VALVE CASING AT SAID OPPOSITE END THEREOF, INCLUDING A PASSAGE IN SAID VALVE CASING THROUGH WHICH SAID AIR FLOWS, A VALVE CONTROLLING THE RATE OF FLOW THROUGH SAID PASSAGE, THERMALLY SENSITIVE MEANS IN SAID VALVE CASING RESPONDING TO A CHANGING TEMPERATURE OF SAID FUEL THEREIN, A CONNECTION BETWEEN SAID THERMALLY SENSITIVE MEANS AND SAID VALVE THROUGH SAID PARTITION TO ADJUST SAID VALVE UNDER CONTROL OF SAID THERMALLY SENSITIVE MEANS RELATIVELY TO SAID PASSAGE, AN OUTLET FOR SAID AIR FROM THE INTERIOR OF SAID HEAT EXCHANGER CASING BETWEEN SAID TUBE SHEETS, SAID OUTLET FOR AIR BEING LOCATED ADJACENT TO THE SAID OTHER ONE OF SAID TUBE SHEETS WHILE SAID ONE PASS ADMITTING AIR TO SAID HEAT EXCHANGER CASING IS LOCATED ADJACENT TO SAID ONE TUBE SHEET, SAID OUTLET FOR AIR AND SAID ONE PASS BEING ON THE SAME SIDE OF SAID HEAT EXCHANGER CASING, AND A BAFFLE IN SAID HEAT EXCHANGER CASING PROJECTING FROM SAID SAME SIDE THEREOF INTERMEDIATE SAID OUTLET FOR AIR AND SAID ONE PASS IN TRANSVERSE RELATION TO SAID TUBES, THE MOVEMENT OF AIR IN SAID HEAT EXCHANGER CASING BEING COUNTER TO THE DIRECTION OF FLOW OF THE FUEL AND AROUND SAID BAFFLE IN GENERALLY CROSS-FLOW RELATION TO SAID TUBES. 